Oil cooler controlling structure



1944- I H. L. CHISHOLM, JR

0111 COOLER CONTROLLING STRUCTURE 3 Sheets-Sheet 1 Fil ed Aug. 1, 1942 July 11', 1944:

H. L. CHISHOLM, JR

OIL COOLER CONTROLLING STRUCTURE s Sheets-Sheet 2 Filed Aug. 1. 1942 y 1944- H. L. CHISHOLM, JR

OIL COOLER CONTROLLING STRUCTURE 3 Sheets-Sheet 3 Filed Aug. 1, 1942 Patented 11, 19 4 on am 1.. 1a, Buflalo. n. Y. mam Ans-n so 4am r ms-4 My inventionrelates to a 'eontrolllhs structure I tor oil coolers, particularly oil coolers usedin connection with hydrocarbon engines. T'such asaircrait engines, for keeping the lubricating oilin the most desirable condition tor eiiicient lubri! cation. 7

The invention relates particularly to improved valving assembly (or controlling the oil flow through the cooler warming Jacket and radiator, and ior controlling the operation of shutters provided on the cooler.

An important object of the invention is to provide a valving assembly in which valves in the path of the oil from the engine are thermostatically set in accordance with temperature to 'con-.

trol the how of the engine oil directly to asump or reservoir or to the cooler, and in which spring resisted valves are interposed in the warming Jacket outlet and the radiator circuit outlet to-be controlled by the iluid pressure to apportion the flow through the jacket and the radiator circuit.

A further object or the inventionis to provide for setting or the cooler shutters in accordance with the pressure of the engine oll'in the inlet end of the valving assembly.

Another object is to provide in the valving assembly a cylinder with .a piston therein con- 61 ,1, showins the thermostatically conrtrolle'dlyalv'esset for low of engine oil to the cooler, and ,fwith the cylinder structure in 0 .to sh e n lnl:

Figure}! is asection plane III-III 0! F18- ure2 showing the controlled valves set no closure against new or the engine oil to cooler and the piston in the cylinder shifted out by the pressure .tor closure-or the coolershutters: ll'igures is a section on plane rv 1v. o! 1"lg-. ure.3:and

.Figure 5 is a section on plane V-V otl 'igure 8.

Referring particularly to time 1, It indicates the rsdiatoistruct'ure and ill the valve structure; The radiator structure shown is or a conventional .t'ybemoniprising the cylindrical shell ll through which tubes il soldered or otherwise together at their ends and exposedviorthe flow therethrough or air during runningoi'the vehicleflor airplane. flurroimding the shell ,II is th'e'i warming jacket I! providing the annularwarmingjspace -l.8 around the shell and connectedlat' its lower sides with the ,torithrough 4|. Mountedfon'top 9 the min: Ju e -l i nleb 'finl m the ivalvees'tructure andis as by screws ll. 1

nected with the cooler shutters, with the move-' ment of the piston controlled by the pressure of the engine oil within the inlet end of the valving assembly.

Still another object is to-provide valve controlled by the pressure of the engine oil in the inlet end of the valve assembly to! inturn a controlling the now 01' this oil into the cylinder for operation oi! the piston therein.

Another object is to provide a valving assem'bly in which the valve chamber receives the oil i'rom the engine and has therein valves thermostatically set to control the flow tothe cooler; and

valve means controlled by the pressure in said valve chamber to'in turn control-the flow. of oil from said valve chamber to the cylindertor operation of the piston to move the shutters in closs ing direction, and with sprin means for moving the piston in direction for opening-oi the :shutters.

The above erhgmerated and other features of my invention aiilincorporated on the accompanying drawings, of which:

Figure 1 is a side elevation, partly inzsection, of an oil cooler with the improved valving assembly mounted thereon; I Figure 2 is an enlarged section on plane'.II II dReier'ring-particularly ;tol"igures 2, '3, 4 and v5, the valvestructure V comprises the Musl m vhaving the inlet il. i.'or the oiiirom theengine. and the outlet jil vfor the returniiiow the radiator and vwarming'jacket to the .irom which thejoil to the engine is Within .thehousing to eitherlside o! the inlet II are the transversewalls {ll andr-l I. between the sidesland top oilthe housing. "Ihelowenendsof transversewalls are'lconnected to the horiwall ,ll entendingnbetweenthe sides of the housing. The walls =21, and, together with 1the,sides:and-top'oi; .l l deilne a valve chamber; 34.

' valve-chamber]! is" inletspaoe' ll', the outlet Partly :surrounding-thewalls which define the v pgg sa gejwaiyjlel'l'qm which registers with the pas- .sageway'fl throughtheebaseillon the warming Jacket, theJacket having the inlet ll -,com,munieating withthe passaseway. ll.

{To :the left so: thevalve chamber '24 is (the .cylindricahspace Q," defined .by' the cylindrical ;portl n-;=n.or =the=housing Ii, andzthe lmilertl'ims- Yverse wall-N,.thefaxislot the space being to one side .of but parallel with'the axis of the -valve chamber. V Communicating withzthe outlet i! is, the outlet chamber 18, defined by the side walls of housing i8 and the walls 81, 89 and 28 and communicating with the valve chamber 1| through the vertical passageway 12. The valve chamber H is defined by the sides and end wall of the housing I8, the cylindrical wall 81, the wall 28 and the housing bottom wall 13, in which valve chamber are located the Jacket outlet valve 14 and the radiator outlet valve 15, the ports 14' and 15 of which register with corresponding ports 48 and 43 in the base or plate l4 on the warming jacket |2, the ports 48 and 43 registering respectively with the'jacket outlet 4| and the radiator outlet 44. The valves 14 and 15 are respectively held againsttheir seats 18 and 11 by the springs l8 and 18 which react against'the guide ca es 88 and 8|.

Slidably operable within the cylindrical chamber 88 is the piston 82 which is rigidly secured to or integral with the piston rod "which hasthe borefl enlarged at its inner-end to provide a valve chamber .X and to leave a shoulder 85.

Surrounding the inner end of the valve chamber is the annularport 88 which'communicates by means of the passageways 81 with the inner end' of the chamber 88 between the piston face and thewall 89. The outer, end of the valve chamber X is connected by the ports 88 with the outer'or low pressure end of chamber 88, this low pressure end being vented to the outlet space'lll through the passageway 89 adjacent to the cylinder head 98 through which the piston rod extends. Interposed between the cylinder head 98 andthe piston82 isthe concentric spring assembly 9| which urges the piston inwardly toward the wall 89.

Slidable at its outer end in the valve chamber X is the hollow valve rod 92 extending slidably through the bearing 93in the wall 89 through the chamber 18 and through the wall 28 into the valve chamber 24. Afiixed to the outer end of the valve rod is the hollow plunger 94 which is 'guided through a bearing bore in the wall 28.

on the outer endof the plunger 94 or on the in- 7 side of the housing. |8'.is a spacer stop such as 95 to assure a passageway for the flow of oil from the chamber 24 into the bore 98 of the valve rod 92. At the inner end of the bore 98 are the ports 91 which, as shown in Figure 2, are normally closed oif from the annular port 88 and the passageways 81 in the piston 82. Interposed between .28 has the passageway therethrough to this outlet space -'|8 which passageway at its inner end is sui'frounded by the valve seat 48, and the wall 2| has the passageway 49 therethrough which at its inner end is surrounded by the valve seat 58. Within the valve chamber 24 there is the valving assembly comprising theannularvalve and the annular valve 52 for cooperating respectively with the valve seats" and 58. Between the valves is a thermostat T which may be of the type known in the trade as the Vernet type. This thermostat comprises the body or 'container 53 from which extends the neck 54 for the plunger f 55 to be acted upon by the thermostatic material 54 extends axially through the valve 52 and has rigidly secured thereto the collar G against which the valve is held by the spring 83 which is interposed between the valves 5| and 52.

Formed on the inner end of the thermostat body 53 is a stud C to which is rigidly secured a sleeve D which at its inner end has a shoulder E. Slidably mounted on the sleeve D is the annular relief valve 8|, the head of which is held against a mating surface 8| on the valve 5| by the walls 28 and 2|. The thermostat is adjusted .so that at temperatures below, say 100 F., the

thermostat will be in its contracted position, and its body together with the valves will be shifted to the right (Figure 3) by the spring 82 for unseating the valve 5| and seating the valve 52.

7 Atthe same time, the thermostat body receives the plunger 55 whose head engages the adjustable abutment screw H in the plug I in the adjacent end wall of housing I8. As the thermostat is subjected to higher temperatures. the material ftherein will expand, and as the spring 89 is stronger than the spring 82, the thermostat body with the valves thereon will be shifted away from the plunger and toward the left for opening of the valve 52 and closing of the valve 5|. As the temperature rises further, the valve 52 will eventually. be fully opened, and the valve 5| will be fully closed (Figure 2). The thermostat may continue to expand after the valve 5| has been seated and, unless means were provided to allow such overtravelthe thermostat body would burst.

To permit overtravel without fracture, the sleeve D, which is attached to the thermostat, slides axially to the left within the relief valve 8|. The

. shoulder E of the sleeve D moves away from the stop fingers F on the valve 5|, and the collar G which is attached to the thermostat pulls the valve 52 further to the left to a position beyond its normal fully opened position.

vOn Figure 1 is diagrammatically shown a supply sump O for the lubricating fluid from which the pump P draws the oil for delivery to the engine E, the oil flowing from the engine through the inlet ll of the valve structure V and returns to the reservoir through the outlet l8.

Describing now the operation, before the engine is started, the temperature in the valve structure V is such that the thermostat T is contracted, as shown on Figure 3, the valves 5| and 52 being respectively open and closed. The thermostat T is adjusted to remain contracted under, say F., and as the engine now starts, the pump P driven thereby will draw oil from the sump 0 and force it through the engine bearings, the oil flowing from the engine into the inlet around the valve assembly and past the open valve 5| through the passageway 41 into the outlet space 18 and from there through the outlet l8 back to the sump. This permits a rapid warming of the oil in the sump since it receives no cooling flow from the radiator. The warmed oil, engaging with the thermostatic element T, raises the temperature thereof above and 30 to the inlet 3| of the warming jacket,

and through the warming jacket out; of the jacket outlet ll and through'the passageway 48 into the valve port 14'. The oil in the radiator being usually sluggish when the engine is started, the resistance to the flow from the engine will cause pressure to build up against the valve 14 in the jacket outlet, and when this pressure has reached, say 30 lbs. per sq. inch, the valve will start to open against the spring 18 for flow from the jacket into the valve chamber H and through the vertical passageway 12 into the chamber and through the outlet l8 back to the sump. During this time, some oil may be forced from the jacket through passage 45 into and through the radiator due to the 30 lb. per sq. inch pressure in the jacket circuit, and past the valve 15 against its spring 18 which is comparatively light, and this flow will enter the valve chamber 1| and join the flow from the jacket tothe outlet I8. This slight flow through the radiator assists in the warming thereof, and as the radiator warms and the resistance to flow through it decreases, the rate of flow increases until a temperature, say 180 F. is reached, the pressurethrough the jacket dropping down below 30 lbs. persq. inch so that the spring 18 closes the valve 14, all of the oil then flowing through the radiator, through the open valve port 15'.

Shouldthe oil in the radiator suddenly'become sluggish or congealed, pressure will again build up in the jacket and the valve "will be opened for flow through the jacket until the: radiator has again become warmed up for normal flow therethrough. Should the oil in both the radiator and the warming jacket suddenly congeal while the valve 5| is held closed by the thermostat T (Fig. 2), the built up pressure will open the relief valve 8| for flow of the engine-oil through the passageway 41 into the outlet space 10 and back to the sump until the pressure built up by the oil from the engine can re-establlsh flow through the jacket.

Describing now the shutter operation, the yoked end I81 oi the piston rod 83 is attached .ters are fully open, the-piston 82 being at the inner end of the cylinder chamber 88 as shown on Figure 2. If there is no pressure in the valve chamber 2l,'the spring 98 will holdthe valve rod 82 and the plunger 94 thereon in outer positlon against the stop 85 (Fig. 2) and the outer end of the valve rod will be between the annular port 88 and the ports 88 to shut off the piston passageways 81 from the valve port 81 which will be closed by the piston. The spring assembly 91 holds the piston at its inner end, and the cooler shutters are held fully open as shown on Figure 1. When the engine is started, pressure is built up in the valve chamber 24 which pressure acts on the head 89 of the valve rod assembly and forces it outwardly against the predetermined load of the spring 88. This outward movement of the valve assembly brings its ports 81 into registration with the annular port 88 for flow of oil from the valve chamber 24 through the bore 96 of the valve-assembly and through the valve ports into the annular port 88 and out position for holding theshutters closed, on ac-.

through the passages 81 into the inner end of the cylinder space 68, and. so. long as the valve assembly moves outwardly for registration of its ports with the annular port 88, the oilwill 'force the piston outwardly against the resistance ofthe springs 9|,the oil in the outer end of the cylinder chamber 88 escaping throughsthe passageway into the outlet chamber 18. The valve rod assembly thus moves outwardly in ac cordance with the pressure in the valve chamber temperature in theradiatordrops, the pressure in the valve chamber 24 necessarytoforce the oil through the radiator will increase, due to the increase in viscosity of the oil, and the valve rod assembly will function in response to the increase in pressure for outward movement of the piston and corresponding closing movement of the shutters and restriction of cooling, air flow through the radiator. -0vertravel of the valve rod with respect to the piston, due to sudden pressurerises, is prevented by the shoulder 85 at the inner end of the valve chamber 88 which actsas a stop for the valve rod, as-shown on Figure 3.

Figure 3 shows the valve rodassembly in its fully outer position with the piston-82 in its outer the oil pressure in its outer position, the end of the valve rod will move outwardly in they valve. chamber X until it exposes the annular port 86 at the inner end of the valve chamber, so that the oil behind thepiston may escape through the passageways 81, the annular port 88, the valve chamber'X, the ports 88 at the-inner end of the valve chamber, and into the outer end of the cylinder chamber .88 and from there out through the passage 88 into the outlet space 10 so that the spring 9| may then shift the piston inwardly to follow the receding movement of the valve rod assembly 92. Should the valve rod stop its receding movement, the movement of the piston by the spring 8| will continue until the annular port 88 in the piston is closed by the end of the valve rod and further escape of oil from the innerend of the cylinder chamber 68 stops. The piston thus accurately follows the various movements of thevalve rod and such movement of the valve rod and piston is in accordance with the pressure perature controls the operation of the shutters.

The application of the varying fluid pressure to the piston is controlled by the valve rod assembly I! which in turn is controlled by'the varying pressure and the spring ll. The valve movement is accurately controlled by the pressure and the piston accurately follows the movement of the valve for corresponding control or the'shuttors.

-I' have-shown a practicaland eilicient embodiment oi the features ofmy invention but I do not desire to be limited to the exact construc- 1 tion, arrangement and operation shown and described, as changes and modifications may be made without departing from the scope of them-- vention. i

I claim as my invention:

1. A contiblling structure for anintemal combustion engine oil cooler having shutters thereon, comprising a cylinder and a piston therein connected with the shutters for operation thereoi, spring means tending to hold said piston at the inner end of said cylinder for opening ofthe shutters, a valve chamber in saidpiston and passageway therefrom into the cylinder behind the piston, tin-axially shiitable valve rodioperable at its in-saidpiston'valve-chamber, said valve 'rod'having 'abore therethrough and a port .ior

connectingthe outer end oi'isaidbore with said piston passageway, spring means tending to hold said valve rod fordi'splacement of its port from said passageway, means providing an inlet chamberior receiving the oil iroin the engine andz'said having "an-outlet for delivery of the en -.1

gine oil to the cooler, a valve in said inlet-cham- "ber ior said outlet and a thermostat responsive tothe iemperature oi the oil in said .i'nlet'chamber for-controlling said valve, said-valve 'ro'd being subjected to the pressureinisaidsinlet chamber'determined by the resistanceto the flo'w from I thermostat an oil cooler comprising a housing on the coder havingan inlet space for receiving the oil to be cooledand having an outlet irom said space to the cooler, a valve for said outlet and a thermostat responsive to the temperature or the oiiin' said inlet space to control said valve, a cylinder taming part of said housing and having a piston therein connected with the cooler shutters for operation thereof; spring means tending to move said piston'to the inner end of said cylinder for opening of the shutters. the pressure in said inlet space being dependent upon the resistance to v flow oi the oil through the cooler, an axially movable valve element extending at its inner end into [said inlet space to be subjected to the pressure therein for outward movement and having a bore therethrough, outward shift of said valve element by the'iluid' pressure in said inlet space aligning said chamber through; the cooler, said pressure being the sole meansiand functioning-independently of the temperature in said valv chamber for shiftingsaid valve rod .forJconnections ofits -port' withsaid rpiston passageway forrflow-of oil under pressure from said chamber -through the valve rod' bore into the cylinder-behind thepiston for outward movement of the piston and-closing movement of the shutters;

2. Controlling structure for-sthe shutters on an 1 internalcombustion engine oil cooler comprising -'a cylinder and a piston'therein connected with the shutters, a" spring tending tozmove the piston ,to the inner end 0! the cy-linder foropening "of 1 the shutters, a valve chamber in said -piston,

passageway through said piston ;from: said valve chamber to the spacebehind-the-piston, a .valve 1 projectingat 'one end into said piston-valve chamber,--a bore through-said valve rod and a port connecting said borewith said'valve chamber, spring means 'nonnallyH-holdingjsaid' valve rod shitted outwardly in saidvalve chamber-aim displacement of its port from said pistonlp'assageway, said valve rod being 'subjected' 'to the 'pres-' I sure of the oilflow from the engine to the" cooler tobe shiftedsolely by the oil pressure'independently of 'and'uninfiuencedby-the temperature 01' said flow for exposure'of its-port to the-piston passageway andfor flow of fluid through said bore and piston passageway into the cylinder behind the piston for outward movement of'the piston for closing movement of the shutters, outward movement of saidpistonbythe fluid pressure relative to said valve rod causing said piston to close said valve rod port until said valverod again =exposes said ports to the-piston passageway, whereby said piston is restrained to follow the movement of said valve rod,"and a valve for the flow from the engine to the-cooler controlled by a' saidvalve "element port with the piston port for =fiow of fluid from said inlet space into the cylinder space behind the piston for outward movementoi' the piston bythe pressure until the pis- Y tonport is "moved out 0! alignment with the valve element port and continued outward movement'offthe valve element will again align said port-for further outward movement of the pistonywherebyfthe outward movement of said piston-follows the outward movement of said valve element for closing movement 01' the shutters under control-oi the fluidpressure in said inlet "space, the-outer end of the cylinder having a I discharge passageway for oil displaced bythe outward movement of the piston, the movement of said valve element being controlled solely by the oil pressure in said inlet space and being uninfluenced bythe oil temperature in said space.

--4. A controlling structure for the shutters on an oil'cooler comprising a housing on the cooler having andnlet space for receiving the oil to be cooled and having an outlet from said space to the cooler,;a valve for said outlet and a thermostat' responsive to the temperature of the oil 7 in said inlet'space to'control said valve, a cylin- "der forming part ofsaidhousing and having a piston therein connected with the cooler shutters ior operation thereof, spring meanstending tomovesaidpistdn' to the inner end of said cylinder for opening'of the shutters, the pressure in said inlet space being dependent upon the resistance to flow of the 0fl through the cooler, an axially movable valve element extending at its inner end into said inlet space to be subjected tothe pressure therein for outward movement and having a bore therethrough for the now of fluid from said inlet space, a spring resisting outward movement of said valve elemerit, -a valve chamber in said-piston into which the outer end'ofsaid valve element-extends, said piston having a port connecting said valve chamher with the cylinder space behind the piston, said valve element having a port at its outer end communicating with the. bore therethrough, outward shift of said valve element by the fluid pressure in said inlet space aligning said valve element responsive to the temperature of such 3. A controlling structure for the shutters port with the piston port for flow of fluid from said inlet space into the cylinder space behind the piston for outward movement of the piston by the pressure until .the piston port is moved out of alignment with the valve element port and continued outward movement of the valve element will again align said port for further outward movement of the piston, whereby the outward movement of said piston follows the outward movement of said valve element for closing move, ment of the shutters under control of the fluid pressure in said inlet space, ,the outer end of the cylinder having a discharge passageway for oil displaced by the outward movement of the piston, said piston structure having a second port controlled by said valve element and connecting said valve chamber with theouter end of the cylinder space,said valve elementduringoutward movement thereof being interposed between said piston ports 'but upon inward movementthereof after an outward movement ofithe piston :strucoutward movement of the valve element recennects said ports for further outward movement of the piston structure, whereby said piston structure is restrained to follow the outward movement of said valve element controlled by the pressure in said inlet space, said valve element during outward movement thereof shutting oil said piston structure ports from each other but during recessional movement thereof after a forward setting of the piston structure exposing said piston structure ports to each other ,for escape of the fluid from the inner end of the cylinder for i ward movement of the pistonstructure by its spring means until inward movement of the pisl Ql t u wr rel t v F h valve cl m n hut .91 suc slow. whereb inward -.m0 eni n o s id istsnstructur m s j l c .th 'r ssi a im v Im o said yalv le emen qbv its s i the movement of ture exposing both pistonports for flUidiflOWgflQm the inner to the outer end'of the cylinder space and inward movement of the piston structure by its spring means until inward movement of the piston relative to the valve element willcause said piston ports to be'disoonnected, whereby the inward movement of said piston structure for opening movement of the shutters follows the recessional movement of said valve element, the movement of said valve element being controlled solely by the oil pressure in said inlet space independently of and uninfluenced by the oil temperature in said space.

5. Control structure for the shutters on an oil cooler comprising a housinghaving an inlet space for receiving the oil to be cooled and having an outlet for flow of the oil to the cooler, a valve for said outlet and a thermostat responsive to the temperature of the oil in said inlet space to control said valve, the pressure in said inlet space being dependent uponthe resistance Of flOW of the oil through the cooler, a cylinder forming, P rt of said housing and having a piston structure therein connected with the shutters for operation thereof, spring means tending'to move the piston structure to the inner end of said cylinder, said piston structure'having a valve chamber therein, a port connecting the outer end ,01 said valve chamber with the inner end. of the, cylin-- der behind the piston, a second port extending from the inner end of said valve chamber to the outer end of the cylinder in advance of the pis ton, the outer end of the cylinder havingaydischarge outlet for oil displaced by outward movement of the piston, an axially movable valve element projecting at its outer end into saidvalve chamber and projecting at its inner end into said inlet space to be subjected to the fluid pressure therein to be moved outwardly, spring means resisting the outward movement of said valve element, said valve element adjacent to its outer end having a port, a passageway through the valve element from said port to the inner end thereof for flow of fluid fromsaid inlet space ,to said valve element port, said valve element port being closed by said piston structure when said valve element is at rest, outward movement of said valve element in said valve chamber bringing said valve element port into alignment with;

' chamber with the cylinder space at opposite sides 1 al? i v ls m sin lc trolled ,solelvy r the ,ai n ssil in a d s ac inde endent y o an jun n e c d by he rtenire ure ssi s ss .6. Controlling structure tor an ,internal combustion engine oil cooler having shutters thereon,.comprisinga,housing having an inlet chamber therein for receiving the oil from the engine, said inlet chamber having an outlet for -flow of oil therefrom to the cooler, valve means in said inlet chamber, thermostat means respon sive to the temperature in said inlet chamber for operating said valve means to control said outlet, the pressure in said inlet chamber being dependent upon'the resistance to flow of the oil through the cooler, a cylinder forming part 01' said housing, a piston in said cylinder connected with the cooler shutters for operation thereof, spring means tending to move said piston inwardly for opening movement or the shutters, means providing a connection for flow oi oil from said inlet chamber into the cylinder behind .said piston for outward movement thereof and closing movement of the shutters, said piston having a valve chamber therein and ports connecting said valve of the piston, acontrol valve movable in said valvechamber and .having a port included in said connection, ioricooperating with the piston ports, said control valve being subjected to I the pressure in said inlet -chamb'er' to be controlled by the pressure in said inlet chamber, formovement for cooperation of, its port with the piston ports for control 01' the oil flow into said cylinder whereby to eiIect movement oisaid piston structure lor control of said. shuttersin accordance with-the pressure in said inlet chamber independently of the temperature in said inlet chamber.

7. Contro1 li ng valve structure for the radiator flow, and warming jacket flow: through the oil cooler foran internal combustionengine, comprising a housing having {an inletv chamber" for to said outlet chamber, acheck valve in said Jacket outflow passageway resisted by a comparative- 1y strong spring and a check valve in said radiator outlet passageway resisted by a comparatively weakcspringfwhereby at ordinary temperature substantially all of the oil now through .the coolerwill-beby wayof the radiator'and whereby, upon increased resistance to flow through the radiator to a predetermined degree, said jacket element will disconnect said ports until further 7 outlet passageway check valve will be opened for ioii flow through thewarming jacket, said inlet a chamber having an outlet to the cooler and having another outlet for flow for flow of engine oil of engine oil to said outlet chamber, a valve assembly in said inlet chamber controlling said outlets, and thermostat means responsive to the temperature in said inlet chamber for controlling said valve assembly, said check valves being closed by excess pressure in saidoutlet chamber when said outlet to the cooler is closed and said outlet to the outlet chamber is open whereby to prevent harmful back pressure into the cooler from said outlet chamber.

8. Controlling bustion engine 'oil cooler having shutters thereon, comprising ahousinghaving an inlet chamber thereinfor receiving the oil from the engine,

said inlet chamber structure ior an internal comd ber (or controlling said having an outlet-tor flow of oil ,therefromio the cooler, valve means in said chamber, thermostat means responsive to the 20 temperature of the oil in said chamber ior operating said valve means to control said outlet, the pressure in said chamber being dependent upon the resistance to'flow of the oil through the cooler, a cylinder forming part of said housing, a piston in said cylinder connected with the cooler shutters for operation thereof, spring means tending to move said piston inwardly for opening movement of said shutters, means providing a connection for fiovv of oil from said chamber into the cylinder 'behind said piston for outward movement thereof and closing movement of the 'shutters, and a valve controlled solely by the pressure in said chamber independently of and uninfluenced by the temperature in said chamoil connection to said cylinder to cause the movement of the piston to be dependent solely upon the oil pressure in said chamber.

HARRY L. CHISHOLM, JRv 

